Pull up revisions:
src/sys/kern/uipc_socket.c revision 1.213
src/sys/kern/uipc_syscalls.c revision 1.160
(requested by christos in ticket #822).
PR/47569: Valery Ushakov: SOCK_NONBLOCK does not work because it does not
set SS_NBIO.
XXX: there are too many flags that mean the same thing in too many places=
,
and too many flags that mean the same thing and are different.